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Simulation of Material Fracture (Material Separation) in Tensile Test

拉伸试验中材料断裂（材料分离）的模拟

基本信息

批准号：
14550089
负责人：
KOMORI Kazutake
金额：
$ 0.77万
依托单位：
Daido Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550089/
关键词：
Plasticity Metal Forming Ductile Fracture Finite Element Method Tensile Test

项目摘要

The head investigator has developed a new computation program using the Finite Element Method (FEM). In other words, a computation program which can separate one node into two nodes when the material fractures has been developed. The behavior of crack propagation after the material fractures can be analyzed using the computation program. In this research, the simulation of material fracture (material separation) in the tensile test which is one of the representative material tests has been performed using the computation program which the head investigator has developed. First, the yield function proposed by Gurson and the evolution equation which is newly proposed by the head investigator and which denotes the change in the void volume fraction is used. Here in the proposed evolution equation, it is assumed that the void nucleates when the non-dimensional hydrostatic stress of the material becomes larger than a certain value. Further the material fracture is judged using the ductile fracture criterion which is proposed by the head investigator and which is based on the microscopic point of view. Finally, the experiment of tensile test was performed and the analytical result is compared with the experimental result. The value of the parameter in the evolution equation is determined so that the analytical result coincides with the experimental result. Hence the evaluation of the material fracture can be achieved by the tensile test.

首席研究员利用有限元方法开发了一种新的计算程序。也就是说，已经开发了一个计算程序，可以在材料断裂时将一个节点分成两个节点。利用该计算程序可以分析材料断裂后的裂纹扩展行为。在本研究中，利用组长开发的计算程序，对具有代表性的材料试验之一的拉伸试验中的材料断裂(材料分离)进行了模拟。首先，采用了Gurson提出的屈服函数和首席研究者新提出的表示空穴体积分数变化的演化方程。在所提出的演化方程中，假设当材料的无量纲静水压应力大于某一值时，空洞就会形核。在此基础上，利用组长提出的基于微观角度的延性断裂判据对材料断裂进行了判断。最后，进行了拉伸试验，并将分析结果与试验结果进行了比较。确定了演化方程中参数的取值，使分析结果与实验结果相吻合。因此，可以通过拉伸试验来评价材料的断口。